SU1637653A3 - Method for struggle against the pests of agricultural plants, cepidoptera noctuides - Google Patents

Abstract

The process consists in treating the crop conjointly with at least one baculovirus from Spodoptera littoralis or Mamestra brassicae and at least one photostable pyrethrinoid. The insecticidal compositions comprises the combination of at least one of the said baculovirus and at least one photostable pyrethrinoid; doses of baculovirus and pyrethrinoid are advantageously below usual doses. Such compositions and process are used to control noctuid Lepidoptera by potentiation of the viroses induced by nuclear polyhedra.

Description

The invention relates to the control of pests of cultivated plants and can be used in agriculture.

The purpose of the invention is to reduce the consumption of the active substance.

Potentiation of viral diseases caused by certain baculoviruses can be achieved by using vaccination of these baculoviruses in combination with light-resistant pyretrinoid. The baculoviruses used are derived from insects Spodoptera littoralis and Mamestra brassicae. The baculovirus strains were isolated in the laboratories of the National Institute of Agrochemical Research and stored in the National Collection of Microorganism Cultures of the Pasteur Institute (Paris) from 1'09.82 under number: 1-203 for baculovirus Spodoptera littoralis, 1-204 for baculovirus Mamestra brassicae.

Of the persistent nirethrinoids, (S) 1-cyano-3-phenoxybenzyl ester 1R, cis-2,2-dimethyl-3- (2,2-dibromovinyl) -cyclopropanecarboxylic acid-deltamethrin, known under the commercial name DECIS, is used the concentration of deltamethrin in which is 25 g / l

As for the baculovirus, the usual recommended dose for use on soil is about 10 polyhedra per hectare.

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Experiments on a cotton plantation, carried out by the association of the baculovirus Mamestra brassicae with deltametrin, allowed us to reveal the synergism of this association, taking as a criterion the yield of cotton - this family. Indeed, the association of the deltametry dose is equal to 1/10 of the normal dose, which is recommended (25 g of active substances per 1 ha) and vaccinations of Mamestra brassicae in 1 polyhedra per 1 ha provided a significant increase in the yield of cotton-seed in relation to the same products consumed separately in the same doses.

Potentiation of the disease by the virus has also been proven in the laboratory by applying the technique of biological experiments on insects taken as a target. This technique of biological experiments consists in subjecting batches of caterpillars at a certain stage of development to infection with increasing doses of baculovirus, or poisoning with increasing doses of pyrrhotinoids.

Experiments were performed on tracks 0 (, 1-better with 30 tracks per batch and 8 repetitions for each experimental option. Различ Different doses of baculovirus subjected to experience are well mixed with the nutrient medium during preparation at the moment when the temperature of this medium reaches 50 ° C in the cooling phase. Then the numbers of polyhedra refer to the volume of the nutrient medium and are expressed by the number of polyhedra per mm3. These different doses of baculovirus can also be deposited on the surface of the nutrient medium using a micropipette in the same way as and high dose amount piretrinoidoVo Then baculovirus and active substance, respectively, are expressed as: polyhedra / / 1 mm2 and 1 ml / mm2.

Insects are grown on this contaminated nutrient medium, in individual cells, in an air-conditioned room, at 25 ° C ± 1, 75-5% moisture ratio and photoperiod at 17 to 24 hours. Mortality is checked every day.

These laboratory tests have shown that potentiation is obtained with a reduced dose of pyrethrinoid and a reduced dose of baculovirus.

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For example, a potentiation of virus disease has been obtained in the laboratory for concentrations of baculovirus isolated from Spodoptera littoralis between DL 50 and DL 30 when using deltametrin as a pyrethrinoid in amounts between DL 10 and DL 20.

Also, when the baculovirus consumed is that isolated from Mamestra brassicae and Peltamethrin is used as the pyrethrinoid, the appropriate doses are as follows: the baculovirus Mamestra brassicae in doses between DL 50 and DL 20, for example, between DL 20 and DL 30; deltamethrin at doses around DL 10 and DL 20;

It must be recalled that the reduction in DL 50 is a lethal dose of 50%, i.e. a dose that causes mortality in 50% of insects. Also, DL 30, DL 20 and DL 10 are lethal doses that cause mortality, respectively, 30, 20 and 10%.

The lethal doses mentioned above for the pyrethrinoid correspond to almost 1/80 of the dose that is usually advised for use on the fields, which is 25 g of the active substance per hectare for delmetretrin.

Typically, doses of pyrethrinoids that are preferred correspond to dilutions of 1/5 to 1/100 of the normal dose advised for a given compound taking into account the conditions of use in the laboratory and in the field.

For baculoviruses, the above lethal doses correspond approximately to values between 1/5 and 1/10 of the normal dose used.

Thus, baculovirus can be consumed in amounts that are less than or equal to the amounts that are usually recommended (10 polyhedra / ha) o

The compositions can be in the form of powders, granules, suspensions, emulsions of solutions for aerosols, baits or other preparations commonly used for insecticidal applications.

Taking into account the polyphagy of these pests, which are mainly the night lepidoptera insects, the field of application of the method does not concern only cotton

plantations, but it also covers soybeans, rice, maize, beets, tobacco, various horticulture, including tomatoes; cabbage, beans; forage crops such as alfalfa and Alexandrian clover, in addition, vineyard, citrus, tea tree, mulberry tree, coffee tree, banana tree, and similar crops that can be affected by nocturnal lepidoptera.

Experiments have shown that potentiation is not obtained with any entomopathogenic virus of any kind, but

Digitally with two baculoviruses Spodoptera littoralis and Mamestra brassicae. In contrast, no potentiation is obtained with baculoviruses that are well studied, such as Lymantria dispar baculovirus, Autographa californica baculovirus and Heliothissp baculovirus. (Elcar). Thus, a very large specificity of compositions was established.

Example 1 The discovery of the fenomena of potentiation of the disease by the virus of the nuclear polyhedrosis of the night lepidopteran insect Spodoptera littoralis while simultaneously infecting it with its own baculovirus and a reduced dose of deltamethrin.

6 options were made to potentiate the proposed composition Untreated control; deltamethrin; parathion methyl; Spodoptera littoralis baculovirus; Spodoptera littoralis baculovirus + deltamethrin; Spodoptera lit-toralis baculovirus + parathion-methyl,

First identified lethal doses of 50 (DL 50) for each product, taken separately, these lethal doses are as follows: 1.2 poly

hedrons per 1 mm3 nutrient intake for caterpillars; 1 ml per 1 mm2 of commercial product, based on deltamethrin; 1.25 x g. Mg per 1 mm2 of parathion-methyl-based commercial product.

To determine the potentiation of the compositions of the invention, the following doses were actually used: 0.6 polyhedra per mm3 for baculovirus (DL 30); 1.25-10 9ml per 1 mm2 deltamethrin (DL 10); per mm2 parathion methyl (DL 1).

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At 50 ° C, the polyhedra is well mixed with the nutrient medium before gelation of the latter, chemical insecticides are deposited with a micropipette on the surface.

In experiments, Spodoptera littoralis caterpillars in stage L 1 were used before molting.

After treatment in a nutrient medium, insects were planted in individual plastic cells, which were placed on this medium, and placed in a climatic chamber (temperature 25 ° С + 1, relative humidity 75-5%, photoperiod 17 for 24 hours).

The sanitary condition was checked every two days until the sixth tracked stage, and the mortality rate was chosen as the criterion of the treatment efficiency.

The treatment efficiency with only chemical insecticides is zero or very weak; the cumulative mortality after 14 days of observation is a maximum of 11% for the deltamethrin variant. Baculovirus one causes mortality of 36%, and it should be noted that approximately the same value was obtained with the same number of polyhedra in association with a reduced dose of parathion-methyl. Mortality reaches 76% when the virus is combined with a reduced dose of deltamethrin. Table 1 summarizes the mean data obtained with different combinations.

Example 2. Experiments with baculovirus Mamestra brassicae.

In example 1, the larvae of the Lepidoptera Mamestra brassicae were simultaneously infected with its own baculovirus and a reduced dose of deltamethrin. Only deltamethrin and only baculovirus were also used as a comparison.

The following results were obtained,%:

Deltamethrin 1/100 ° trade preparation

Baculovirus Mamestra brassicae, 100 polyhedra per 1 mm3 of medium22 Deltamethrin — baculovirus (in the same doses) 46 These results show that there is potentiation of the disease by the deltamethrin-Baculovirus Mamestra brassicae virus.

EXAMPLE 3: Identification of Specific Formulations.

They also acted with other bacillus viruses and found that there was no reduction of the disease by the virus, such as that observed with Spodoptera littoralis Mamestra brassicae.

Simultaneous infection of epidoptere Heliothis armigera caterpillars with their jg bacterial baculovirus and a reduced dose of deltamethrin,%: Deltamethrin, 1/100 h. Of the trade preparation 47 Heliothis15 vacuvirus

armigera 0,2 polyhedra / mm227 Deltamethrin - baculo virus11 Simultaneous infection of caterpillars 20 by their own baculovirus and a reduced dose of deltamethrin,%: Deltametrin, 1/100 hours of commercial preparation 2 Lyumetria baculovirus, 25 1 polyhedron / mm2 10 Deltamethrin - baclulovirus , 1 polyhedron / mm2 9 Simultaneous infection of caterpillars of 30 Heliothis virescens with their own baculovirus (ELCAP) and a reduced dose of deltamethrin,%: Deltamethrin, 1.80 h. Trade preparation, 38 Baculovirus Heliothis, 0.2 polyhedron / mm2 19 Deltamethrin - baculo virus 36 40 PRI me R 4. Acted according to example 1, Dhu other tracks. The following results, as well as consumed doses,%:

On caterpillars Spodoptera frugiper- da

Deltamethrin 1/80 ° 57

Baculovirus Mamestra,

40 polyhedra / mm220

Baculovirus del 50

tamethrine (same doses) 93

On the tracks of Heliothis armigera

Deltamethrin 1/80 ° 24

Baculovirus Mamestra,

0.4 polyhedra / mm211

Baculovirus - deltamethrin (same doses) 20

On the tracks of Heliothis virescens

Deltamethrin 1/10018

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Baculovirus Mamestra, 4 polyhedra / mm245

Baculovirus Mamestra -f- f-deltamethrin (same doses) 87

On tracks Spodoptera littoralis

Deltamethrin 1/100 ° 53

Baculovirus Mamestra, 1000 polyhedra / mm28

Baculovirus - Deltamethrin (same doses) 59

On caterpillars Spodoptera exigua Deltamethrin 1/100 ° 46

Baculovirus Mamestra,

0.1 polyhedra / mm211

Baculovirus Mamestra f t-deltamethrin (same doses) 57

Baculovirus Mamestra, 0.4 polyhedra / mm211

Baculovirus Mamestra - Deltamethrin (same doses) 71

On the tracks Ostrinia nubilalis Deltamethrin 1/80 ° 13

Baculovirus Mamestra, 1000 polyhedra / mm2O

Baculovirus Mamestra 4-f-deltamethrin (same doses) 23

On tracks Lymantria dispar Deltamethrin 1/100 ° 2

Mamestra baculovirus, 28000 polyhedra / mm215

Baculovirus Mamestra - Deltamethrin (same doses) 8

Baculovirus Mamestra brassicae is potentiated deltamethric in other insects than the initial insect eroi, i.e. Lepidoptera insects Spodoptera frugiperda, Spodoptera exigua and Heliothis virescens This potentiation does not take place on Heliothis armigera, Spodoptera littoralis, Ostrinia nubilalis and Lumantria dispar.

Example 5. Investigation of the activity of the method on Spodoptera caterpillars in paddy plantations. The experiments were carried out on small plots of rice plantation land of 60 m2 with the following amounts of depamethrin (1 g of active substance / ha) and baculovirus Mamestra brassicae (1 g of virus / ha), respectively: 0.4 + 330.2 + 330.4 + 330, 6 + 300 and 2 + 165. These experiments were repeated 4 times.

These experiments gave the following results (see tab.2) „

Thus, synergism using the baculovirus Mamestra brasicae and pyrethrinoid is confirmed.

Example 6. The baculo virus used is that of Spodoptera littoraliso. The pyrethrinoid is deltamethrin and the results are expressed in percent mortality of the larvae of the same Spodoptera littoralis (see Table 3).

The ratio between the baculovirus weight and the number of polyhedra is represented as follows: 1 g 0.003 / 13 ° polyhedra, 10 g 0.03 x 10 polyhedra;

100 g 0.31013 polyhedra; 165 g 0.5x10 polyhedra; 300 g 1 x 10 polyhedra.

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Claims (1)

Invention Formula A method for controlling pests of agricultural plants of Lepidoptera noctuides, including the treatment with an active substance, which is characterized in that, in order to reduce the consumption of the active substance, a mixture (ZE-3-phenoxy-y-cyanobenzyl ester ( 1K) -cis-3- (2,2-dibromovinyl) - 2,2-dimethylcyclopropanecarboxylic acid and baculovirus Spodoptera littoralis 1-203 or Mamestra brassicae 1-204 (National collection of cultures of microorganisms of the Pasteur Institute) at the rate of 0.4-5 g / ha and (0.03-1) polyhedra / ha, respectively, I Table 1 The result obtained has a value with risk The result obtained has a value with risk Table2 errors in 5% errors in 1%. Table3